Gastric cancer is one of the major causes of cancer-related death worldwide. Familial clustering is observed in about 10% of cases; 1-3% of cases are hereditary. In the latter group, a syndrome which has been well characterised is hereditary diffuse gastric cancer; this is specifically associated with CDH1 (E-cadherin) germline mutations in about 30% of families. In this article, the state of the art of familial gastric cancer regarding the clinical, molecular and pathology features is reviewed, as well as the practical aspects for a correct diagnosis and clinical management.